Low vapor permeability container closure including push-out tab for forming pour mouth and method for making same



Sept. 27, 1966 oss ET AL 3,275,203

LOW VAPOR PERMEABILITY CONTAINER CLOSURE INCLUDING PUSH-OUT TAB FOR FORMING POUR MOUTH AND METHOD FOR MAKING SAME Filed July 19, 1965 2 Sheets-Sheet 1 w "I i Q N" W INVENTORS.

Fifi 50 NOJJAL 1724/1 WE/N AAA $22; @52 ATTOIQV 5 Sept. 2'7, 1966 F. NOSSAL ETAL 3,275,203

LOW VAPOR PERMEABILITY CONTAINER CLOSURE INCLUDING PUSH-OUT TAB FOR FORMING POUR MOUTH AND METHOD FOR MAKING SAME Filed July 19, 1965 2 Sheets-Sheet 2 FIG. 7

FIG. 9

INVENTORS FRED JVOJJAL MAX 1525 IN ATTORNHE' United States Patent LOW VAPOR PERMEABHLITY CONTAINER CLO- SURE INCLUDING PUSH-OUT TAB FOR FORM- ING POUR MGUTH AND METHOD FOR MAK- ING- SAME Fred Nossal, Brooklyn, and Max Klein, Bronx, N.Y., as-

signors to Ferdinand Gutmann & Co., Brooklyn, N.Y., a corporation of New York Filed July 19, 1965, Ser. No. 472,816 "7 Claims. (Cl. 222-541) This invention relates to a low vapor permeability container closure including a push-out tab for forming a pour mouth and to a method for making the same.

It is an object of our invention to provide a low vapor permeability container closure including a push-out tab for forming a pour mouth wherein the closure securely seals the mouth of the container against passage of matter therethrough, including air borne water vapor, as long as material is stored in said container in its as-sold condition.

it is another object of our invention to provide a container closure of the character described wherein the pushout tab is defined by a weakened zone that forms the periphery thereof so that the tab can be easily and conveniently displaced from the plane of the closure to create when desired a pouring outlet which facilitates withdrawal of material from said container.

It is another object of our invention to provide a container closure of the character described wherein once the push-out tab thereof is displaced the same can not be precisely restored to its original condition whereby a visual inspection of the closure will immediately indicate whether the same has been the subject of tampering.

It is a further object of our invention to provide a container closure of the character described wherein even after the push-out tab has been displaced from the inner seal of the closure, the other components of the closure can reclose the mouth to inhibit the passage of material therethr-ough.

It is another object of our invention to provide a container closure of the character described wherein the closure includes: (1) an inner seal of low vapor permeability completely closing the container mouth and having its peripheral margin adhered to the rim of the neck of the container by a joint of low vapor permeability and (2) a cushion liner superimposed over and in face to face contact with the inner seal, the cushion liner being bonded to the inner seal by a continuous and heat-fluidifia'ble imperforate layer of low vapor permeability during the shelf life of the container and before the container is opened. The cushion liner and inner seal serve as a single unitary moisture barrier which is broken only when the cap of the container is removed. The inner seal includes a pushout tab defined by a weakened zone and lying Wholly within the continuous narrow area at which the inner seal is adhered to the mouth of the container, said zone and the heat diuidifiable layer of low vapor permeability material being so interrelated that, as long as the cushion liner and inner seal are bonded to one another, the presence of the weakened zone does not disturb the integrity and the water vapor impermeability of the closure.

It is yet another object of our invention to provide a container closure of the character described wherein the push-out tab is defined by a score line which does not destroy or even impair the integrity and low vapor permeability of the closure and yet which provides a weakened zone to facilitate the formation of a pour mouth in said closure that enables convenient flow of the stored material to take place from the container, The scoring die must pass at least partially through and may pass completely through the inner seal of the closure and even slightly into the cushion liner of the closure. Upon the latter two occurrences, the material of the facing of the cushion liner reseals the break in the closure so as to maintain the integrity of the closure.

It is an additional object of our invention to provide a container closure of the character described wherein the push-out tab for forming the pour mouth is so constructed that even when said mouth is opened, the tab remains attached to the closure and stays in the position into which it has been depressed whereby no part of the tab falls into the material stored within the container and the tab does not hang loosely and thereby interfere with outward flow of the stored material.

It is still a further object of our invention to provide a suitable method for manufacturing a container closure of the character described wherein the method includes quick and economical steps for forming the closure and securing the same to the mouth of a container.

In general, and in accordance with the teaching of our invention, we provide a container closure which includes a push-out tab for forming a pour mouth, the closure being specifically intended to cap containers storing various fluent materials wherein it is desired to prevent the ingress and egress of liquid in vapor state. The container closure includes three basic components: a laminated inner seal, the peripheral margin of which is bonded to the rim of the neck of the container, a cushion liner superimposed over and lightly bonded to the inner seal and a cap that encloses the inner seal and cushion liner and that threads tightly to the neck of the container.

The inner seal preferably comprises a three layer flexirble composite laminated by two mastic barriers of low vapor permeability. More specifically, the inner seal desirably includes two coextensive outer layers the surfaces of which have a low mastic absorption and between which is interposed a coextensive layer of soft metallic foil. The foil on each side thereof is adhered to the outer layers by wax barriers. The inner seal completely closes the mouth of the container and is secured to the rim of the neck of the container by a conventional adhesive.

The underside of the inner seal has provided therein a score line which penetrates the inner seal through one or more of its layers including the layer nearest the stored material. Because of a plugging effect of the heatfiuidifiable facing of the cushion liner, the score line in no instance destroys the vapor barrier integrity of the closure.

The score line defines the body of a tab in the inner seal except for its base. The tab when pushed through the remainder of the inner seal is displaced from the plane of the inner seal along a weakened zone engendered by the score line and leaves a pour mouth in said inner seal through which the material stored in the container can be conveniently dispensed. The score line and tab defined thereby lie wholly within the zone at which the inner seal is secured to the mouth of the container.

The cushion liner includes a stiff yet flexible thick cushioning (resilient) ibody layer, which has a continuous coherent i.e. unbroken, imperforate heat fiuidifia'ble adhesive facing of low vapor permeability. Said facing is preferably Wax and is directly superimposed over and abuts the top layer of the inner seal. When the container closure is made, the wax facing of the cushion liner is heat and pressure sealed to and thereby is lightly adhered to the inner seal so as to preserve the integrity of the closure despite the presence of the push-out tab. During manufacture the scoring die penetrates at least the layer of the inner seal adjacent to the stored material and possibly all layers of the inner seal and even enters the wax facing. However, the wax facing at the time the weakened zone is formed or subsequently is in a fluid state and flows into, i.e. plugs, any break in the inner seal or any break or thinning in the wax facing so that a? when the wax facing hardens after manufacture of the closure, the integrity of the closure is maintained intact.

When our container closure is first emplaced over a container with material therein, the peripheral margin of the inner seal is secured by a conventional adhesive such as a starch adhesive to the rim of the neck of the container. Superimposed over the inner seal is the cushion liner, with the wax facing of the cushion liner lightly adherent to the top layer of the inner seal over the entire contacting faces thereof. Over both the inner seal and cushion liner is the metal cap, with its internally threaded s-kirt mating with the neck of the container and with the crown of the cap pressing the cushion liner and the inner seal against the rim of the neck. In such condition, the container with its stored material securely holds said material. At this time, the inner seal and the cushion liner, despite the pressure of the weakened zone along the outline of the tab and due to the plugging action of the wax facing, constitute a single unitary assembly providing an internal vapor barrier during the shelf life of the container, which effectively seals the container against passage of vapor.

When it is desired to remove some or all of the contents of the container, the cap is unscrewed from the neck of the container. An inwardly directed protrusion on the skirt of the cap lifts the cushion liner and strips it from the inner seal and thereby exposes the inner seal. The inner seal remains adhered to the container to which it is bonded more strongly than the cushion liner adheres to the inner seal. At this point, visual inspection of the inner seal will immediately reveal whether anyone has tampered with the inner seal or removed any portion of the contents of the container. That is, if the tab is bent downwardly and a pour mouth has been formed in the inner seal, it will be obvious that someone has previously opened the mouth of the container.

When it is desired to remove some of the contects of the container, the tab is merely pushed out from the inner seal along the weakened zone formed by the score line, downwardly into the neck of the container. The tab bends on its end (base) near the periphery of the inner seal but inwardly of the zone where the inner seal is secured to the mouth of the container and remains in this position due to the soft quality of the metal foil layer of the inner seal. Thereafter, the container may be tilted sothat the contents of the container flow out in a controlled manner through the pour mouth formed in the inner seal, the inner seal having a laminated construction of such nature that it will maintain itself in an out-of-the-way position and the outflow of the contents will not restore it to an interfering position. When it is desired to reclose the container, the cap is merely rethreaded onto the neck of the container, with the cushion liner being pressed by the cap against the inner seal to form an adequate cover during the usage life of the containers contents.

These and various other objects and advantages of our invention will become apparent to the reader in the following description.

Our invention accordingly consists in the features of construction, combinations of elements, arrangements of parts and series of steps which will be exemplified in the container closures and method for making the same herein after described and of which the scope of application will be indicated in the appended claims.

In the accompanying drawings in which are shown various possible embodiments of our invention,

FIGS. 1 and 2 are, respectively, side elevation and top plan views of an apparatus for making our container closure;

FIGS. 3 and 4 are top plan views of the inner seal with a push-out tab defined therein by a weakened zone in the inner seal, in the former figure the score line which engenders said weakened zone not penetrating the top layer of the inner seal and in the latter figure of the score line passing through said top layer;

FIG. 5 is a vertical cross sectional exploded view of our container closure with the pour mouth having been formed in the inner seal;

FIGS. 6 and 7 are greatly enlarged fragmentary transverse cross sectional views of the inner seal and cushion liner, each illustrating the step of utilizing a different die for forming a slit in the respective inner seals;

FIG. 8 is a view similar to FIGS. 6 and 7 but illustrating in dot and dash lines the depth of penetration of a die which has cut into the wax facing of the cushion liner and in full lines the final condition of the facing of the cushion liner after it has plugged the break caused by the score line; and

FIG. 9 is a fragmentary view similar to FIGS 3 and 4 but with the score line interruptively cutting through the top layer of the inner seal. 7

Referring now in detail to the drawings and more specifically to FIGS. 3, 5 and 6, the reference numeral 10 denotes our container closure including a push-out tab for forming a pour mouth. In the drawings, the container closure 10 is illustrated in connection with a container in the form of a jar 12 suitably formed from any rigid imperforate material from which containers are conventionally made. Typically, the jar is made from glass.

The contents of the container may constitute almost any material, but the container closure is especially suitable for fluent material where it is desired to prevent egress or ingress of air borne water vapor before the container is opened. The closure has particular usefulness in the packaging of granular or pulverulent materials which need to be protected against exposure to moisture or atmospheric air. Such materials may include those of a hygroscopic nature.

The container constitutes a hollow thin walled body 14 which is in one piece with a hollow neck 16. In the drawings, the neck is illustrated as being smaller in diameter than the remainder of the body. However, this configuration is but one suitable form of a glass jar 12 with which our invention may be utilized. The neck has circums-cribing it on its exterior surface a complete or interrupted male thread 18, said thread as is conventional being formed of the same material as is the body of the jar and said thread being in one piece with the body of the jar. The neck has an upper annular boundary, ie a rim 20 which defines the opening of said container.

The closure includes as a component thereof a flat circular inner seal 22. The periphery of the inner seal is slightly larger in diameter than the outside diameter of the rim 20 so that the peripheral margin 21 of said inner seal extends beyond and overhangs the rim. (See FIG. 5.) The inner seal is formed from a strong low vapor permeability sheet material and is of a multi-layer laminated construction.

As seen in FIG. 6, the inner seal includes two spaced outer film layers, to wit, a bottom film layer 24 (uppermost in FIG. 6 which is inverted) proximate to the material stored in the container and a top film layer 26 distant from the stored material. Said layers may be exemplificatively formed from 25 lb. glassine sheets, the term 25 lb. being the weight of a ream of 24" x 36" glassine sheets. The broad internal opposed faces of the glassine layers and the upper face of the top layer are glossy. The film layers may also be formed from other cellulosic or synthetic films, as for example polyethylene, cellulose acetate, and polyvinylidenechloride.

In a preferred form of our invention, the inner seal 22 includes an intermediate layer 28 formed from thin sheet metal foil. The metal foil layer is interposed between the proximate and distant film layers 24, 26 and, in an acceptable form, the metal foil layer is /3 mil in thickness and is aluminum. The metal foil layer is. soft (dead) so that when the push-out tab is displaced from the plane of the inner seal, the tab will retain its deformed configuration.

Interposed between the top and bottom film layers 24, 26 is at least one mastic barrier. Where the inner seal is composed of only two layers there is only one mastic barrier interposed between and bonding the film layers. Where a metal foil layer is interposed between the two film layers, there are two mastic barriers, one of said mastic barriers 31 adhering the top film layer 26 to the metal foil layer while the other mastic barrier 30 adheres the bottom film layer 24 to the metal foil layer. Both of the film layers, the metal foil layer and the mastic barriers are coextensive. The inner faces of the film layers each defines a plane boundary of a mastic barrier, with the finish or the constitutions of said film layers preferably inhibiting absorption of mastic by said film layers.

The mastic barriers are flexible, tacky at room temperature, have a low vapor permeability characteristic and serve to securely bond the film and metal foil members to one another. The mastic may be composed of a wax, a resinous laminant, or a resinous adhesive, all of which are extensively commercially used for this purpose. The barriers, if wax, are each suitably of /2 mill thickness.

The foregoing inner seal material is commercially known and available and is referred to in the trade as double-ply wax laminated glassine, this being the form without an intermediate metal foil layer. A basic weight of 40/47 pounds is mentioned by way of suitable example, this term designating that each glassine layer is of a pound weight so that with a two ply lamination, the glassine weight is 40 pounds which is laminated with 7 pounds of wax.

The inner seal material with an intermediate metal foil layer is also commercially known and available and is designated in the trade as Triplex wax laminated aluminum foil. The aluminum foil layer is suitably of from /3 to one mil thickness and said laminated aluminum foil has an approximate basis weight of from about 63 pounds to about 135 pounds, again this being the weight of a ream of 24" X 36" sheets.

The peripheral margin 21 of the broad flat face of the inner seal proximate the stored material is bonded along a continuous narrow zone Z to the rim 20 of the neck 16 of the container 14 as by a suitable cement, e.g. a starch adhesive. This bond is of low vapor permeability and is quite strong. It may be so strong that the material of the bottom layer will shred beforethe bond releases the peripheral margin of the inner seal from said nm.

The inner seal 22 has formed therein a score line 36 which defines the major portion of the boundary of a push-out tab in one piece and coplanar with said seal In .one embodiment of our invention as seen most clearly in FIGS. 3 and 6 the score line 36 constitutes a narrow slit 40 which runs continuously through the bottom proximate film layer 24 and not through the top distant film layer 26. The slit 40 also passes through the mastic barrier 3% which joins the film layer 24 to the metal foil layer 28 and it also passes through said metal foil layer. Of course, the portions of the silt in each of the mentioned layers are in registry since, as will be subsequently described, the slit is made by a single downward stroke of a scoring die.

In another embodiment of our invention, and as illustrated in FIGS. 7 and 9, the score line comprises a narrow slit 70 extending through the bottom proximate film layer 24, the intermediate metal foil layer 28, the mastic barrier 30 which joins said proximate film layer, to the metal foil layer the other mastic barrier 31 and the top distant film layer 26. However, the slit is not continuous but, rather, is interrupted, like a line of dashes. That is to say, and as seen 'most clearly in FIG. 9, substantially 6 co-equal segments of the inner seal are alternatively cut and not cut, it being understood that the segments follow the path of the slit 70.

With the interrupted segments of the scroe line passing through the top distant film layer, it is even easier to push out the tab 38 from the inner seal.

In a third embodiment of our invention, as illustrated in FIGS. 4 and 8, the score line comprises a slit 73 that passes completely through all the layers of the inner seal and may even extend partially into the facing 58 of the cushion liner. The dot-and-dash lines at the top of the slit 73 as at 75 illustrate the depth into the facing to which the scoring die penetrated before withdrawal, while the solid line defining the end of the slit as at 77 illustrates the final, hardened, flowed-in position of the facing in this area.

It should be observed that due to the slight thicknesses of the laminae of the inner seal and to the fact that when the scoring line is formed by a scoring die the inner seal is supported on the resilient cushion liner, the depth of the slit cannot be precisely controlled over the entire length thereof. Hence part of the slit may extend through the aluminum layer 28 and stop short of penetrating the upper layer 26, part of the slit may extend through the upper layer 26 and part of the slit may extend into the facing 58. Therefore all depths of penetration may be considered as a single embodiment and the alternative embodiment may be considered as that in which the slit is interrupted.

In each embodiment and regardless of the depth of cut, the slit 4% initiates from a location at 42 adjacent to and radially inwardly from the periphery of the innerseal and inward from the zone Z where the inner seal is bonded to the rim of the neck 16, then includes a short reach 44 which defines one side of the rectangular base 46 of the tab, then includes a circular segment 48 which is a major arc of a circle and then is completed by another short reach 50 which defines the other side of the base 46 of the tab. The reach 50 likewise terminates inwardly of the zone Z.

The base of the tab is integral (continuous) with the remainder of the inner seal. Other configurations for the tab are also suitable. It will be observed that the entire slit is spaced inwardly from the zone Z.

The slit lies entirley within the neck of the container and said score line constitutes a weakened Zone in the inner seal which facilitates breaking the main body portion of the tab 38 from the remainder of the inner seal. When the tab 38 is pressed downwardly, it bends on the end of the base of the tab 38 continuous with the remainder of the inner seal. When the tab is pushed out of the plane of the inner seal an aperture 52 is formed in the inner seal of an area substantially less than the opening of the mouth of the container. The aperture constitutes a pour month which is located adjacent the wall of the container but does not cross the same and which serves to facilitate the controlled dispensation of stored material out of the container.

Superimposed over the inner seal 22 and in face to face bonded contact therewith over its entire area is a cushion liner 54. The cushion liner is flat, stiff yet somewhat flexible, cushiony (resilient), circular and coextensive with the inner seal.

The cushion liner includes a relatively thick resilient body layer 56 which is formed from paper, pressboard, pulpboard, newsboard, felt board, composition cork or like suitable materials. The body layer 56 of the cushion liner has a continuous adhesive imperforate facing 58 with a low vapor permeability characteristic, said facing being fluidifiable, e.g. under the influence of heat, and being solid under ambient conditions, i.e. at room temperature. The facing 58 typically includes a mixture of amorphous wax, a microcrystalline wax and paraffin. The cushion liner may be formed from a conventional stock known in the trade as waxed pulpboard. If de- .sired, a synthetic resin film may be interposed between the body layer and the adhesive facing of the cushion liner.

The adhesive imperforate facing 58 of the cushion liner is superimposed directly over and is lightly bonded over its entire area to the top distant film layer 26 of the inner seal. The adhesive bond between the facing 58 and the distant film layer 26 is substantially more readily separable than is the bond between the peripheral margin 21 of the inner seal and the rim 20 of the container 14 at the zone Z.

In the embodiment illustrated in FIGS. 3 and 6 wherein the slit 40 does not penetrate the top distant film layer 26, the facing 58 by its low vapor permeability and adherence to the inner seal reinforces the unimpaired integrity of the container closure during its shelf life. In the embodiments illustrated in FIGS. 4 and 8, and 9 and 7 wherein the slit passes, respectively, through the inner seal including its film layer distant from the stored material and partially into the cushion liner facing, and interruptively through the top distant film layer, the material of the facing seals the slit so as to prevent vapor passage therethrough whereby the integrity of the closure remains unimpaired.

A screw-type cap 60 fits over the unitary assembly of the cushion liner 54 and the inner seal 22. The cap 60 is conventionally formed from a self-form-maintaining material, metal being customary for this purpose. The cap includes a flat circular crown 62 which is substantially coextensive with the cushion liner and the inner seal. The cap further includes a cylindrical annular skirt 64 which is dependent from the crown and which has formed therein an internal female screw thread 66. The screw thread 66 is matable with the male thread 18 on the external surface of the neck 16.

On the skirt of the cap 60 adjacent the crown 62 is an annular radially inwardly directed protrusion 68 which is spaced from the crown a distance at least about equal to the combined thickness of the unitary assembly comprised of the inner seal 22 and the cushion liner 54. The protrusion 68 has a diameter somewhat smaller than the diameter of the inner seal and cushion liner and said protrusion, when the cap is screwed onto the container, underlies the peripheral margins of both the inner seal and cushion liner.

When the closure 10 initially is incorporated onto the container 12 and as long as the 'cap has not been removed from the container, a tamper proof low vapor permeability internal seal is effected. This includes the inner seal which is composed of a laminate of low vapor permeability, which seal is bonded to the rim of the neck of the container by a bond of low vapor permeability. Located over the inner seal and with its imperforate adhesive facing of low vapor permeability facing 58 lightly bonded to the inner seal is the cushion liner 54. The inner seal and the cushion liner at this time become a single unitary double thick vapor wall. Over both the inner seal and cushion liner is the cap 60. When the cap is tightly screwed to the neck 16 of container 14, the crown of the cap presses' both the cushion liner and the inner seal against the rim of the neck.

Because the slit 40 is disposed wholly within the zone Z and the facing 58 closes the slit in the instances where said slit penetrates the top distant film layer, the integrity and low vapor permeability of the unitary assembly of the inner seal and cushion liner as a whole is maintained in an unimpaired condition so long as the cushion liner is not raised off the inner seal. Moisture vapor is not able significantly to penetrate the assembly from the back of the cushion liner or through the layer of the inner seal closest to the product from the edge of the inner seal toward the center by wicking action.

When the cap is unscrewed from the neck, the inward protrusion 68 slips by the overhang of the inner seal, the inner seal remaining stationary and fixed to the neck by the secure bond of its marginal periphery to the rim 8 of the neck, 'but'engages the marginal periphery of the facing of the said cushion liner and strips the cushion liner from the inner seal, since the bond between these two components is relatively light. It may be noted that the cushion liner thereafter remains within the cap constrained by the inward protrusion 68.

Upon the removal of the cap 60 with the cushion liner, the inner seal is completely exhibited to view and a visual inspection thereof immediately and clearly reveals whether the tab 38 has been broken out along the score line 36.

When it is now desired to remove some of the contents of the container, the tab is simply pushed through the remainder of the inner seal consequently breaking along the weakened zone so that it hangs stifiiy down into the neck of the container. (See FIG. 4.) The dead (soft) quality of the intermediate metal foil layer retains the tab in its deformed state. So that it will not interfere with the outward flow of contents. With the tab so located, a pour mouth is formed in the inner seal and when the container is tipped, a controlled stream will pass from the interior of the container through the pour mouth to the exterior of the container.

Turning now to the method of making the container closure 10, and referring specifically to FIGS. 1 and 2, there is provided an elongated web 74 of laminated sheet material wound in a supply roll 76 from which web the inner seals 22 will subsequently be formed. There is also provided another elongated wax faced web 78 of like width which is wound in a supply roll 80 from which the cushion liners 54 will subsequently be formed. The supply rolls 76, 80 are both rotatably mounted on parallel shafts 82, '84. The supply rolls '76, 80 are unwound in the directions, respectively, A and B and the webs are guide-d into face-to-face contact by passing between two pairs of rollers 86, 88. The webs 74, 78 are intermittently driven along the length of an elongated bed in the direction C by the rollers 88.

The supply rolls are oriented so that the web 74 is superimposed over the web 78 with the imperforate facing 58 of the cushion liner web 78 upward and in faceto-face contact with the inner seal web 74.

The webs '74, 78 are 'heat sealed to one another and for this purpose there is provided a conventional heat sealing unit 92. The facing 58 is heat-activatable and upon a raise in its temperature transforms from a solid into a fluid state. The heat sealing unit is suitably energized from a source 96 of electric power which is connected to a heating resistor 98. The resistor is located in and heats a platen 100 over a bed 90 to activate the adhesive facing on the cushion liner. The webs are pressed against one another to seal them together by the rolls 88. The heat produced by the resistor 98 and the pressure of the rolls 88 combine to bond the webs to one another across their entire contacting faces.

At a location further along the bed 90 and after the webs have been heat sealed, a conventional scoring die 102 such as a clicker rule die mounted on a vertically movable ram 103 forms the slit 40 (or 70, 72) in the inner seal web 74. As previously mentioned, the depth of the cut made by the die 102 is controlled so that the scoring die cuts at least through the bottom proximate film layer 24 and through the intermediate metal foil layer 28 of the inner seal web and may for at least a part of the score line cut through the top distant film layer 26 of said web and optionally into the imperforate wax facing 58.

In the embodiment illustrated in FIGS. 7 and 9, another rule die 104 is utilized which incorporates equally spaced downwardly depending teeth 106. The depth of cut with the die 104 is controlled so that the teeth 106 interruptively cut through the inner seal web but do not cut through the facing 58 of the cushion liner web. The force of the die may cause a crease in the facing and the body of the cushion liner web as at 108.

The scoring dies 102, 104 operate on the webs 74, 78 while they still are Warm and the wax facing 58 still fluid so that where the slit 70 penetrates the distant (top) film layer 26 said slit is reclosed (plugged) by the wax facing which solidifies upon cooling to room temperature to maintain unimpaired the integrity of the closure.

-It will be appreciated that during the manufacturing process, the depths of scoring is diflicult to control with accuracy, especially in view of the extreme thinness of the inner seal. For example, where the slit is intended to penetrate through the film layer nearest the stored material and some intermediate layers, the slit in a significant percentage of the production run may pass for at least a part of the boundary of the tab through the top distant layer and even into the facing of the cushion liner. Similarly, where the slit is intended to pass through only the inner seal, it may penetrate partially into the facing. In all these instances, once the scoring die is removed, the fluidized facing flows back into the slit in the cushion liner so as to prevent vapor passage.

Where the scoring dies does not pass through the uppermost film layer 26 the fluid state of the wax facing at the time of scoring still is an important factor inasmuch as after the facing is locally thinned by the pressure of the scoring die at the weakened zone, the fluid state of the facing will cause the facing automatically to be restored to approximately its original thickness after the scoring pressure has been removed and the facing has resolidified upon cooling to room temperature.

A conventional blanking die 109 mounted on another ram 110 slightly beyond the platen simultaneously blanks out the inner seal 22 and the cushion liner 54 as a single unit from their respective heat bonded webs 74, 78 with the slit 40 (or 70 or 73) previously formed therein.

An intermittently movable carrier 112 is disposed beneath the blanking die 109 and supports a train of spaced inverted caps '60. Each cap is oriented with its crown 62 flat against the belt.

The carrier and the blanking die are timed and coordinated so that the blanking die at the end of the blanking stroke presses the now formed inner seal and cushion liner into the cap 60, past the protrusion 68 with the cushion liner being placed in contact with the crown 62 and with the inner seal immediately above and bonded to the cushion liner.

When it is desired to provide a tamper proof and low vapor permeability closure for a container in which ma terial is located, the cap is simply screwed onto the neck of the container. In a previous step, the starch adhesive has been placed either on the rim of the neck or the peripheral margin of the bottom face of the inner seal so that when the inner seal is brought into contact with the rim by the threaded engagement of the cap to the neck of the container, a firm bond between .the inner seal and the rim is obtained at the same time the cap is screwed onto the container.

It thus will be seen that we have provided container closures and a method of making the same which achieve the several objects of our invention and which are Well adapted to meet the conditions of practical use.

As various possible embodiments might be made of the above invention, and as various changes might be made in the embodiments set forth, it is to be understood that all matters herein described or shown in the accompanying drawings are to be interpreted as illustrative and not in a limiting sense.

Having thus described our invention, we claim as new and useful and desire to secure by Letters Patent:

1. In a method for making a tamper proof low water vapor permeability closure for a container in which material is stored, the steps of:

(a) providing a web of strong flexible inner seal sheet material having two strong film layers and at least one inter-posed mastic barrier of low water vapor permeability bonding the layers, each of said film layers having a face bonded to and defining a different plane boundary of a mastic barrier;

(b) providing a web of flat stiff resilient liner material, said material having a low water vapor permeability normally solid, heat-fluidifiable facing;

(c) lightly bonding by heat and pressure sealing the web of inner seal material to the Web of liner material with the facing of the liner material fluidified in face-to-face contact with the inner seal material;

(d) while the webs still are warm and the facing fluid cutting a slit constituting a score line in the web of inner seal material, said score line defining the boundary of the body of a tab, said slit running through at least the film layer adapted to be disposed proximate to the stored material and not through the liner material, said score line constituting a weakened zone in the web of inner seal material, the pressure of cutting displacing the fluid facing in the region of the slit;

(e) after the cutting permitting the fluid material to flow back and cool so as to restore upon resolidification any impairment of integrity of the closure; and

(f) blanking the bonded webs around each score line -to form a unitary assembly including a single unitary circular inner seal and a circular coextensive liner bonded thereto.

2. A method as set forth in claim :1 wherein at least a portion of the slit extends through the web of inner seal material and wherein after cutting the fluid material of the facing flows into said portion and upon subsequent cooling and solidification plugs said portion to restore the integrity and low water vapor permeability that were impaired by the formation of the slit.

6. A closure for a container having a neck terminating in an open mouth, said closure including:

(a) a low Water vapor permeability flat circular multilayer laminated flexible sheet inner seal completely overlying and closing said mouth;

(b) a low water vapor permeability bond securing the seal completely around its periphery to the rim of the mouth;

(c) a low water vapor permeability flat circular stiff resilient liner coextensive with and superimposed over the inner seal, the liner having a margin jutting radially outwardly of the rim of the mouth;

(d) the liner having a facing which is in face-to-face contact with the inner seal;

(c) said facing being solid at room temperature and forming a bond between the liner and the inner seal, said facing being fluidifiable upon the application of heat;

( f) the bond between the inner seal and the rim being stronger than the bond between the liner and the inner seal so that when the liner is pulled away from the container it will separate from the inner seal and the inner seal will remain connected .to the rim;

(g) a slit in the inner seal;

(h) said slit defining the boundary of the body of a tab except for its base, said base being integral with the inner seal;

(i) said slit running through at least the lamination of the inner seal proximate to the interior of the container and ending short of the surface of the liner distant from the interior of the container;

(j) said slit being disposed wholly inwardly of the rim and being formed while the facing is fluidified by heating and can flow back from a displaced location in the vicinity of the slit .to solidify upon cooling and restore any impairment of the integrity of the inner seal and liner whereby as long as the liner is bonded to the seal the integrity and low vapor permeability of the closure is maintained;

(k) said slit providing a weakened zone in the inner seal to facilitate bending of the tab about its base away from the remainder of the seal so as to leave an 1 1 Opening of restricted area for the dispensing of any material stored within the container; and

(l) a skirted cap threadedly engaging the neck of the container, the crown of the cap pressing the liner against the inner seal and the cap having an internal protrusion spaced from and near the crown and underlying the jutting margin of the liner so that when the cap is unscrewed from the neck the cap strips the liner from the seal and holds the liner near the crown of the cap.

4. A closure as set forth in claim 3 wherein the inner seal is [formed from material including two strong film layers, a soft metal foil layer interposed .therebetween, each said first-named layers being bonded to the foil layer by a low Water vapor permeability mastic barrier, the slit running through at least the film layer proximate to the interior of the container and through the foil layer.

5. A closure as set forth in claim 3 wherein the slit runs completely through the inner seal and is plugged by the resolidified cooled facing of the liner. 6. A closure as set forth in claim 3 wherein the slit con- 1 Z? stitutes a series of perforations extending through the inner seal, said perforations being plugged by the resolidified cooled facing of the liner.

7. A closure as set forth in claim 3 wherein the slit has at least a portion running through the inner seal, said portion being plugged by the resolidified cooled facing of the liner.

References Cited by the Examiner UNITED STATES PATENTS 2,543,181 2/1951 Land 95--8 2,946,478 7/ 1960 Clair et al 220-54 2,991,913 7/ 1961 Goth 222153 3,097,124 7/1963 Demenbery 154-44 3,155,285 11/1964 Van Baarn 222153 3,173,580 3/ 1965 Campbell 222107 3,217,951 11/1965 Paal 222528 ROBERT B. REEVES, Primary Examiner.

20 N. L. STACK, Assistant Examiner. 

3. A CLOSURE FOR A CONTAINER HAVING A NECK TERMINATING IN AN OPEN MOUTH, SAID CLOSURE INCLUDING: (A) A LOW WATER VAPOR PERMEABILITY FLAT CIRCULAR MULTILAYER LAMINATED FLEXIBLE SHEET INNER SEAL COMPLETELY OVERLYIING AND CLOSING SAID MOUTH; (B) A LOW WATER VAPOR PERMEABILITY BOND SECURING THE SEAL COMPLETELY AROUND ITS PERIPHERY TO THE RIM OF THE MOUTH; (C) A LOW WATER VAPOR PERMEABILITY FLAT CIRCULAR STIFF RESILIENT LINER COEXTENSIVE WITH SAID SUPERIMPOSED OVER THE INNER SEAL, THE LINER HAVING A MARGIN JUTTING RADIALLY OUTWARDLY OF THE RIM OF THE MOUTH; (D) THE LINER HAVING A FACING WHICH IS IN FACE-TO-FACE CONTACT WITH THE INNER SEAL; (E) SAID FACING BEING SOLID AT ROOM TEMPERATURE AND FORMING A BOND BETWEEN THE LINER AND THE INNER SEAL, SAID FACING BEING FLUIDIFIABLE UPON THE APPLICATION OF HEAT; (F) THE BOND BETWEEN THE INNER SEAL AND THE RIM BEING STRONGER THAN THE BOND BETWEEN THE LINER AND THE INNER SEAL SO THAT WHEN THE LINER IS PULLED AWAY FROM THE CONTAINER IT WILL SEPARATE FROM THE INNER SEAL AND THE INNER SEAL WILL REMAIN CONNECTED TO THE RIM; (G) A SLIT IN THE INNER SEAL; (H) SAID SLIT DEFINING THE BOUNDARY OF THE BODY OF A TAB EXCEPT FOR ITS BASE, SAID BASE BEING INTEGRAL WITH THE INNER SEAL; (I) SAID SLIT RUNNING THROUGH AT LEAST THE LAMINATION OF THE INNER SEAL PROXIMATE TO THE INTERIOR OF THE CONTAINER AND ENDING SHORT OF THE SURFACE OF THE LINER DISTANT FROM THE INTERIOR OF THE CONTAINER; (J) SAID SLIT BEING DISPOSED WHOLLY INWARDLY OF THE RIM AND BEING FORMED WHILE THE FACING IS FLUIDIFIED BY HEATING AND CAN FLOW BACK FROM A DISPLACED LOCATION IN THE VICINIITY OF THE SLIT TO SOLIDIFY UPON COOLING AND RESTORE ANY IMPAIRMENT OF THE INTEGRITY OF THE INNER SEAL AND LINER WHEREBY AS LONG AS THE LINER IS BONDED TO THE SEAL THE INTEGRITY AND LOW VAPOR PERMEABILITY OF THE CLOSURE IS MAINTAINED; (K) SAID SLIT PROVIDING A WEAKENED ZONE IN THE INNER SEAL TO FACILITATE BENDING OF THE TAB ABOUT ITS BASE AWAY FROM THE REMAINDER OF THE SEAL SO AS TO LEAVE AN OPENING OF RESTRICTED AREA FOR THE DISPERSING OF ANY MATERIAL STORED WITHIN THE CONTAINER; AND (L) A SKIRTED CAP THREADEDLY ENGAGING THE NECK OF THE CONTAINER, THE CROWN OF THE CAP HAVING THE LINER AGAINST THE INNER SEAL AND THE CAP HAVING AN INTERNAL PROTRUSION SPACED FROM AND NEAR THE CROWN AND UNDERLYING THE JUTTING MARGIN OF THE LINER SO THAT WHEN THE CAP IS UNSCREWED FROM THE NECK THE CAP STRIPS THE LINER FROM THE SEAL AND HOLDS THE LINER NEAR THE CROWN OF THE CAP. 